March 2009

Recent Developments in the Field of

Ejection Seat Parachutes

Adrian Jones Ph.D

Director of Engineering

Objective

• Present the Capabilities of the Airborne Systems Aeroconical Parachute

– Type 5000

• Decribe the work conducted in the last 5 years on ejection seat parachutes

– Type 6000 Parachute JSF – MBA Mk16E

– Slotted parachutes

• Look forward to the work to be conducted next

– Type 5000 Light Weight– Future Airborne Systems New Jersey Programme

Background

• There have been many advances in the

science of Ejection Seat Escape systems.

• The parachute has an important part to play

in surviving an escape.

• Many systems use 30 year old designs of

parachute and deployment systems.

• Select and Deselect steering required

• Training Required to optimize advantages

• To simplify the design of other aspects of the

Escape system.

• Reduce sensitivity to deployment conditions.

• Improve Escape window (including increased

pilot mass).

• Embody the advances in modern

Technologies and materials.

Parachute Design Engineer

Goals

Main Parachute Wish List

• Instant Maximum deceleration

– Regardless of speed and height

– within acceptable physiological limits

– for the duration required to achieve Vt

• 1g exactly for flight duration

– No oscillation

– Self steering to avoid obstacles

• Soft zero approach speed landings

The ASE Aeroconical Parachute

Inflation Control Band

Low Permeability Crown

Medium Permeability Lower

Canopy

LeMoigne Slot

LIMIT Technology

• The IGQ Aeroconical Parachutes

prevent excessive opening loads.

• Open in “fast” mode at low speed

• Open in “slow” mode at high Speed

The ASE Aeroconical Parachute

Inflation Control Band

Parachute Vent

Kevlar reinforced

Parachute Hem

Kevlar reinforced

LeMoigne Slot

Selectable Drive

Water Pocket

T5000 “Squidded” State

The Aeroconical Parachute

• LIMIT opening characteristics.

• Select drive

• Select Steering

• De-Selectable Steering and drive

• Acceptable rate of descent

• Acceptable weight and bulk

• Tolerant to damage and

mishandling in use

Maneuverability

• Select Drive by full control deflection

• Release controls to obtain full drive

– Forward Speed 8 ft/S

• Release one control to obtain Max turn

– Turn rate 20 degrees/S (18 Secs/Full Turn)

• Both turn and Drive De-selectable by full deflection of both Controls.

So that’s the Background!

• T6000 development and testing has absorbed much of the effort over the last 5 years

• Slotted Parachutes

– Sponsored by MoD / QinetiQ

– Morphing the Aeroconical profile with a K36 style parachute

• Full slots to the hem (creating 4 arms)

• Crown slots – convensional hem

B25 “Pacific Princess” – Test Platform

Instrumented Pipeman Test Dummy

Early Phase Parachute Deployment

Slotted “Maltese Cross” Aeroconical Parachute

B25 “Pacific Princess” – Test Platform

Eloy Az

Full slot to hem

with control band

Partial slot from

ICB to top of

Panel 1

inflation control

band

Extended Skirt Maltese Cross – late stage inflation

Standard Profile Type 6000 with Inflation Control Band and Crown Slots

Slotted Aeroconical 337lb suspended, 200 Knots

Headline Conclusions

• Slotted Aeroconical capable of very high velocity deployment (~300kts)

– Below 25g resultant

• Slotted Parachutes in General

– Tendency to Arm Tuck – Arm control bands required

– Tendency to rotate – build tolerance?

– Greater edge binding / seam area leads to an increase in weight and bulk

• T6000 with Slotted Crown

– Slight increase in performance did not warrant the increased complexity of construction

So what’s Next

• Type 5000 Light Weight

– Displace Type 1000 with a parachute more

aligned to today’s crew size

– Affordability of modification high priority

Light Weight Aeroconical

• Requirement Summary

• T1000 Parachute in Mk 10 seat being used with heavy pilots (300lb suspended) – high RoD (~27fps).

• New parachute needs to:-– Be capable 144lb (130lb desirable) - 300lb (RoD, 0-0, max g

etc)

– Pack into current Mk 10 headbox using wine press / tooling (T1000 weighs 12.6lbs)

– Have same repack cycle (no pyrotechnics)

• Options:– Retain duplex drogue or change to lighter drogue

• Duplex drogue is heavy / bulky but is a qualified product

• NACES type ribbon or guide surface drogue would require less volume but delta qualification more complex

Existing System. T1000 Duplex Drogue

MBA photograph

ASE T5000 vs T6000 vs T5000LW

T5000 T6000 T5000LW

Parachute Mass 13.0 lb 14.5 lb 11.9 lb

Number of Gores 20 24 20

Flying Diameter 21.3ft 23.5ft ~21.3ft

Constructed Area 673 ft2 808 ft2 673 ft2

T5000 vs T6000 vs T5000LWT5000 T6000 T5000LW

Max Mass 291 lb 337 lb ~300 lb

Min Mass 139 lb 144 lb ~130 lb

RoD (fps) 22.5 at 291 lb 21.5 at 337 lb ~22.5 at 300 lb

Stressing 27.5g at 291 lb 27.5g at 337 lb ~27.5g at 300 lb

Max Drive 8fps at 291 lb 8fps at 337 lb ~8fps at 300 lb

Light Weight Aeroconical – Test Hardware

• 1st Phase Testing took place in Eloy Az, Jan 2009.

• T5000LW

• T5000 Parachute with weight reduction measures– Heavy crown fabric replaced with lighter material

– Kevlar reinforcing removed from cross seams below ICB

– Water pocket construction / attachment redesigned

– Heavier T6000 vent tape used – strength contingency

• Drogues– MBA 5’ Drogue + extractor, ASE guide Surface + extractor

T5000LW / 5’ Drogue

T5000LW / Guide Surface Drogue

Heavyweight high speed drop

Preliminary Results

• Parachute opening performance very

encouraging

– low g but with relatively quick opening time

• Excellent parachute strength

– Drogue bridle to crown attachment method

proven to be robust – tested at 338lbs

• Good Rate of Descent

– Lower 2/3 of canopy flying slightly more

open – increase suspended weight to

300lb with no detectable increase in RoD

Next Stage Testing

• Martin Baker Meteor Tests

– 2 system level tests – conducted March 09

• ASE B25 Testing

– 6 high speed tests (3 heavy 3 light) – now

• Man Rating Testing

– May / June 09, ~30 tests

– Live jump – June 09

• MBA System Level Testing

– Late Summer 09 (TBC)

ASNJ Future Programme

• Develop a Ram Air parachute system

capable of Ejection Seat Use.

– Deploy in a fully braked condition – if pilot

is unable to fly the parachute total velocity

should be the same as current ejection

seat parachutes

– Escape and Evasion capability vastly

increased in most circumstances.

– Possibly sequence opening using a

parachute mounted electronic sequencer

March 2009

Recent Developments in the Field of

Ejection Seat Parachutes

Adrian Jones Ph.D

Director of Engineering